feat: solve part 1 of puzzle 3

04/Scratchcards.Tests/CardTests.cs

@@ -0,0 +1,105 @@
+namespace Scratchcards.Tests;
+
+public class CardTests
+{
+  [Theory]
+  [MemberData(nameof(TestData.ParseCardData), MemberType = typeof(TestData))]
+  public void Parse_GivenInput_ItShouldReturnExpectedCard(string input, Card expected)
+  {
+    var result = Card.Parse(input);
+    result.Should().BeEquivalentTo(expected);
+  }
+
+  [Theory]
+  [MemberData(nameof(TestData.GetCardValueData), MemberType = typeof(TestData))]
+  public void GetCardValue_GivenCard_ItShouldReturnExpectedValue(Card card, int expected)
+  {
+    var result = card.GetCardValue();
+    result.Should().Be(expected);
+  }
+
+  public static class TestData
+  {
+    private static readonly Dictionary<string, Card> TestCards =
+      new()
+      {
+        {
+          "Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53",
+          new Card(
+            1,
+            [41, 48, 83, 86, 17],
+            [83, 86, 6, 31, 17, 9, 48, 53]
+          )
+        },
+        {
+          "Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19",
+          new Card(
+            2,
+            [13, 32, 20, 16, 61],
+            [61, 30, 68, 82, 17, 32, 24, 19]
+          )
+        },
+        {
+          "Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1",
+          new Card(
+            3,
+            [1, 21, 53, 59, 44],
+            [69, 82, 63, 72, 16, 21, 14, 1]
+          )
+        },
+        {
+          "Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83",
+          new Card(
+            4,
+            [41, 92, 73, 84, 69],
+            [59, 84, 76, 51, 58, 5, 54, 83]
+          )
+        },
+        {
+          "Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36",
+          new Card(
+            5,
+            [87, 83, 26, 28, 32],
+            [88, 30, 70, 12, 93, 22, 82, 36]
+          )
+        },
+        {
+          "Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11",
+          new Card(
+            6,
+            [31, 18, 13, 56, 72],
+            [74, 77, 10, 23, 35, 67, 36, 11]
+          )
+        },
+      };
+
+    public static IEnumerable<object[]> ParseCardData =>
+      TestCards
+        .Select(kvp => new object[] { kvp.Key, kvp.Value })
+        .ToList();
+
+    public static IEnumerable<object[]> GetCardValueData()
+    {
+      for (var i = 0; i < TestCards.Count; i++)
+      {
+        var currentCard = TestCards.ElementAt(i);
+        var expectedValue = i switch
+        {
+          0 => 8,
+          1 => 2,
+          2 => 2,
+          3 => 1,
+          4 => 0,
+          5 => 0,
+          _ => throw new Exception("Unexpected card index"),
+        };
+
+        yield return new object[]
+        {
+          currentCard.Value,
+          expectedValue
+        };
+      }
+    }
+  }
+}

04/Scratchcards.Tests/GlobalUsings.cs

@@ -1 +1,2 @@
 global using Xunit;
+global using FluentAssertions;

04/Scratchcards.Tests/PuzzleSolverTests.cs

@@ -0,0 +1,42 @@
+namespace Scratchcards.Tests;
+
+public class PuzzleSolverTests
+{
+  private readonly PuzzleSolver _sut = new();
+
+  [Theory]
+  [MemberData(nameof(TestData.SumCardValuesData), MemberType = typeof(TestData))]
+  public void SumCardValues_GivenCards_ItShouldReturnExpectedValue(string[] cards, int expected)
+  {
+    var result = _sut.SumCardValues(cards);
+    result.Should().Be(expected);
+  }
+
+  public static class TestData
+  {
+    private static string[] Input => File.ReadAllLines("INPUT.txt");
+
+    public static IEnumerable<object[]> SumCardValuesData =>
+      new List<object[]>
+      {
+        new object[]
+        {
+          new[]
+          {
+            "Card 1: 41 48 83 86 17 | 83 86  6 31 17  9 48 53",
+            "Card 2: 13 32 20 16 61 | 61 30 68 82 17 32 24 19",
+            "Card 3:  1 21 53 59 44 | 69 82 63 72 16 21 14  1",
+            "Card 4: 41 92 73 84 69 | 59 84 76 51 58  5 54 83",
+            "Card 5: 87 83 26 28 32 | 88 30 70 12 93 22 82 36",
+            "Card 6: 31 18 13 56 72 | 74 77 10 23 35 67 36 11",
+          },
+          13,
+        },
+        new object[]
+        {
+          Input,
+          23235,
+        },
+      };
+  }
+}

04/Scratchcards.Tests/Scratchcards.Tests.csproj

@@ -27,4 +27,10 @@
     <ProjectReference Include="..\Scratchcards\Scratchcards.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Content Include="..\INPUT.txt">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+
 </Project>

04/Scratchcards.Tests/UnitTest1.cs

@@ -1,10 +0,0 @@
-namespace Scratchcards.Tests;
-
-public class UnitTest1
-{
-    [Fact]
-    public void Test1()
-    {
-
-    }
-}

04/Scratchcards/Program.cs

@@ -1,2 +1,95 @@
-// See https://aka.ms/new-console-template for more information
+namespace Scratchcards;
-Console.WriteLine("Hello, World!");
+
+public class Program
+{
+  public static async Task<int> Main(string[] args)
+  {
+    if (args.Length is 0)
+    {
+      Console.WriteLine("Please provide a path to the input file.");
+      return -1;
+    }
+
+    if (File.Exists(args[0]) is false)
+    {
+      Console.WriteLine("The provided file does not exist.");
+      return -2;
+    }
+
+    var puzzleSolver = new PuzzleSolver();
+
+    var input = await File.ReadAllLinesAsync(args[0]);
+    var result = puzzleSolver.SumCardValues(input);
+
+    Console.WriteLine($"The sum of all card values is {result}.");
+
+    return result;
+  }
+}
+
+public class PuzzleSolver
+{
+  public int SumCardValues(string[] cards) => cards
+    .Select(Card.Parse)
+    .Sum(c => c.GetCardValue());
+}
+
+public class Card(
+  int id,
+  List<int> winningNumbers,
+  List<int> numbers
+)
+{
+  public int Id { get; init; } = id;
+  public List<int> WinningNumbers { get; init; } = winningNumbers;
+  public List<int> Numbers { get; init; } = numbers;
+
+  public int GetCardValue()
+  {
+    var commonNumbers = WinningNumbers.Intersect(Numbers).ToList();
+
+    return commonNumbers.Count is 1
+      ? 1
+      : (int)Math.Pow(2, commonNumbers.Count - 1);
+  }
+
+  public static Card Parse(string input)
+  {
+    var parts = input.Split(':');
+    var cardId = int.Parse(
+      parts[0].Split(
+        ' ',
+        StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries
+      )[1]
+    );
+
+    var numberStrings = parts[1].Trim();
+    var numberParts = numberStrings
+      .Split('|')
+      .Select(s => s.Trim())
+      .ToArray();
+
+    var winningNumbersString = numberParts[0];
+    var numbersString = numberParts[1];
+
+    var winningNumbers = winningNumbersString
+      .Split(
+        ' ',
+        StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries
+      )
+      .Select(s => s.Trim())
+      .Select(int.Parse)
+      .ToList();
+
+    var numbers = numbersString
+      .Split(
+        ' ',
+        StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries
+      )
+      .Select(s => s.Trim())
+      .Select(int.Parse)
+      .ToList();
+
+    return new Card(cardId, winningNumbers, numbers);
+  }
+}